1. Field of the Invention
The present invention relates to a main amplifier and a semiconductor device including the same, and more particularly to a main amplifier and a semiconductor device including the same, which is capable of significantly reducing the number of main amplifiers for amplifying data signals from local input/output lines and outputting the amplified data signals to global input/output lines, for miniaturization and high integration of semiconductor memory devices.
2. Description of the Related Art
Dynamic random access memory (DRAM) is a volatile memory device for storing data in cells each including one transistor and one capacitor. A data input/output operation, which is a basic function of a DRAM cell, is conducted by an on/off operation of a word line, which is a gate input of a transistor in a cell.
FIG. 1 shows the internal configuration related to data input/output operation in a semiconductor device. As shown in FIG. 1, a memory cell in a general DRAM device includes a plurality of memory banks. A read operation for data stored in each cell in a cell matrix MAT of each memory bank BANK0, BANK1, BANK2 and BANK3 is conducted when cell data amplified by sense amplifiers in a sense amplifier array SA is loaded on respective local input/output lines connected to the sense amplifiers, amplified by main amplifiers MA0, MA1, MA2 and MA3, and transmitted to a DQ block through global input/output lines gio0, gio1, . . .
FIG. 1 shows an x8 device having 8 input/output lines as an example of a semiconductor device. Each memory bank BANK0, . . . , BANK3 requires 8 main amplifiers MA. Thus, four memory banks require a total of 32 main amplifiers.
Accordingly, the minimal number of main amplifiers required for the conventional DRAM device corresponds to the multiplication of the number of memory banks by the number of input/output lines. Accordingly, in the case of a graphic memory using an x16 device having 16 input/output lines or a x32 device having 32 input/output lines, at least 64 or 128 main amplifiers are required for four memory banks.
Accordingly, since the memory device having the configuration as described above requires a number of main amplifiers, there is a problem in that a large area for peripheral devices except for the memory cells is required. This problem becomes substantial in DRAM having multi-bank or multi-input/output line structure. In addition, due to this problem, the conventional semiconductor device also has a problem in that it is difficult to set layout pitches of sense amplifiers of a memory code and the like properly.